Stress of many types appears to be linked to obesity apparently due to its link with inflammation. Researchers at Ohio State University have identified another source of obesity related stress as polluted air. Mice exposed to particulate air polution (seven times higher than typical ambient air in Columbus, OH) gained weight whether they were on a normal diet or a high fat diet. A study investigating the link of polluted air early in life with overweight and obesity looked at mice over a period matching childhood in humans. The mice also developed insulin resistance and had higher levels of a marker of inflammation TNF-alpha. Pollution may act as a trigger for obesity like other stressors. If so, this may be yet another reason why moving to urban areas is associated with weight gain.
Source: Arterioscler Thromb Vasc Biol, Dec 2010; 30: 2518 – 2527